CN113287235A

CN113287235A - Laser cavity device, gas laser device, and method for manufacturing electronic device

Info

Publication number: CN113287235A
Application number: CN201980088626.3A
Authority: CN
Inventors: 石井卓也; 伊藤贵志; 鲸凉太
Original assignee: Aurora Advanced Laser Co ltd
Current assignee: Aurora Advanced Laser Co ltd
Priority date: 2019-02-26
Filing date: 2019-02-26
Publication date: 2021-08-20
Anticipated expiration: 2039-02-26
Also published as: JPWO2020174571A1; US11588291B2; US20210336404A1; CN113287235B; WO2020174571A1; JP7273944B2

Abstract

The cavity device for laser may have: a tube of dielectric; an inner electrode extending in the longitudinal direction of the tube and disposed in the through hole of the tube; an external electrode including a contact plate extending in a longitudinal direction of the tube and contacting an outer circumferential surface of the tube, and a step portion formed of a plurality of strip members having one ends connected to the contact plate, the plurality of strip members being arranged in parallel in the longitudinal direction of the contact plate; and a plate spring extending in the longitudinal direction of the tube and pressing the external electrode against the tube, wherein the plate spring includes a plurality of plate spring pieces divided by slits cut from an edge portion in the longitudinal direction of the tube, the plate spring pieces include a bent portion bent along the edge portion, and the strip member is pressed on the edge portion side of the bent portion.

Description

Laser cavity device, gas laser device, and method for manufacturing electronic device

Technical Field

The present disclosure relates to a laser cavity apparatus, a gas laser apparatus, and a method of manufacturing an electronic device.

Background

In recent years, in a semiconductor exposure apparatus (hereinafter referred to as "exposure apparatus"), with the miniaturization and high integration of a semiconductor integrated circuit, improvement in resolution has been demanded. Therefore, the wavelength of light emitted from the exposure light source has been reduced. In general, a gas laser device is used as an exposure light source instead of a conventional mercury lamp. For example, as a gas laser device for exposure, a KrF excimer laser device that outputs a laser beam of ultraviolet light having a wavelength of 248nm and an ArF excimer laser device that outputs a laser beam of ultraviolet light having a wavelength of 193nm are used.

As a new-generation exposure technique, immersion exposure in which a space between an exposure lens and a wafer on an exposure apparatus side is filled with a liquid has been put into practical use. In this liquid immersion exposure, the refractive index between the exposure lens and the wafer changes, and therefore the wavelength of the external appearance of the exposure light source becomes short. When liquid immersion exposure is performed using an ArF excimer laser apparatus as an exposure light source, ultraviolet light having a wavelength of 134nm in water is irradiated onto a wafer. This technique is called ArF immersion exposure or ArF immersion lithography.

The natural oscillation amplitude of the KrF excimer laser device and the ArF excimer laser device is wide and is about 350-400 pm. Therefore, when a projection lens is formed using a material that transmits ultraviolet light such as KrF or ArF laser light, chromatic aberration may occur. As a result, the resolution is reduced. Therefore, it is necessary to narrow the line width of the laser light output from the gas laser device to such an extent that chromatic aberration can be ignored. Therefore, in order to Narrow the Line width, a Narrow-band Module (Line Narrow Module) including a Narrow-band element such as an etalon or a grating may be provided in a laser resonator of the gas laser device. Hereinafter, a laser device whose spectral line width is narrowed is referred to as a narrowed laser device.

Documents of the prior art

Patent document

Patent document 1: specification of U.S. Pat. No. 9748727

Patent document 2: specification of U.S. Pat. No. 8712302

Disclosure of Invention

One embodiment of the present disclosure may be a cavity device for laser, including: a tube of dielectric; an inner electrode extending in the longitudinal direction of the tube and disposed in the through hole of the tube; an external electrode including a contact plate extending in a longitudinal direction of the tube and contacting an outer circumferential surface of the tube, and a step portion formed of a plurality of strip members having one ends connected to the contact plate, the plurality of strip members being arranged in parallel in the longitudinal direction of the contact plate; and a plate spring extending in the longitudinal direction of the tube and pressing the external electrode against the tube, wherein the plate spring includes a plurality of plate spring pieces divided by slits cut from an edge portion in the longitudinal direction of the tube, the plate spring pieces include a bent portion bent along the edge portion, and the strip member is pressed on the edge portion side of the bent portion.

Another aspect of the present disclosure may be a gas laser apparatus including a laser cavity apparatus, wherein the laser cavity apparatus includes: a tube of dielectric; an inner electrode disposed in the through hole of the tube; an external electrode including a contact plate extending in a longitudinal direction of the tube and contacting an outer circumferential surface of the tube, and a step portion formed of a plurality of strip members having one ends connected to the contact plate, the plurality of strip members being arranged in parallel in the longitudinal direction of the contact plate; and a plate spring extending in the longitudinal direction of the tube and pressing the external electrode against the tube, wherein the plate spring includes a plurality of plate spring pieces divided by slits cut from an edge portion in the longitudinal direction of the tube, the plate spring pieces include a bent portion bent along the edge portion, and the strip member is pressed on the edge portion side of the bent portion.

In addition, another aspect of the present disclosure may be a method of manufacturing an electronic device, in which a gas laser apparatus having a laser chamber apparatus generates laser light, outputs the laser light to an exposure apparatus, and exposes the laser light on a photosensitive substrate in the exposure apparatus to manufacture the electronic device, the laser chamber apparatus including: a tube of dielectric; an inner electrode disposed in the through hole of the tube; an external electrode including a contact plate extending in a longitudinal direction of the tube and contacting an outer circumferential surface of the tube, and a step portion formed of a plurality of strip members having one ends connected to the contact plate, the plurality of strip members being arranged in parallel in the longitudinal direction of the contact plate; and a plate spring extending in the longitudinal direction of the tube and pressing the external electrode against the tube, wherein the plate spring includes a plurality of plate spring pieces divided by slits cut from an edge portion in the longitudinal direction of the tube, the plate spring pieces include a bent portion bent along the edge portion, and the strip member is pressed on the edge portion side of the bent portion.

Drawings

Several embodiments of the present disclosure will be described below as simple examples with reference to the drawings.

Fig. 1 is a schematic diagram showing a schematic configuration example of the entire manufacturing apparatus used in an exposure step in the manufacture of an electronic device.

Fig. 2 is a schematic diagram showing a schematic configuration example of the entire gas laser apparatus.

Fig. 3 is a cross-sectional view of the cavity apparatus perpendicular to the direction of travel of the laser.

Fig. 4 is a perspective view showing the dielectric tube, the inner electrode, the outer electrode, and the plate spring.

Fig. 5 is a cross-sectional view of the dielectric tube, the inner electrode, the outer electrode, and the plate spring perpendicular to the traveling direction of the laser light.

Fig. 6 is a diagram showing a state in which the outer peripheral surface of the dielectric tube is deformed.

Fig. 7 is a diagram showing a state of uneven wear of a part of the outer electrode.

Fig. 8 is a perspective view showing the dielectric tube, the inner electrode, the outer electrode, and the plate spring of the cavity device in embodiment 1.

Fig. 9 is a sectional view showing the dielectric tube, the inner electrode, the outer electrode, and the plate spring of the cavity device in embodiment 1.

Fig. 10 is a view of the dielectric tube, the external electrode, and the plate spring of the cavity device in embodiment 1 as viewed from a direction perpendicular to the longitudinal direction of the dielectric tube.

Fig. 11 is a diagram illustrating a state in which the outer peripheral surface of the dielectric tube is deformed in embodiment 1.

Fig. 12 is a diagram showing a state of uneven wear of a part of the outer electrode in embodiment 1.

Fig. 13 is a sectional view showing the dielectric tube, the inner electrode, the outer electrode, and the plate spring of the cavity device in embodiment 2 by the same method as fig. 5.

Fig. 14 is a perspective view showing a dielectric tube, an inner electrode, an outer electrode, a plate spring, and a 2 nd guide of the cavity device in embodiment 3.

Detailed Description

1. Description of manufacturing apparatus used in exposure process of electronic device

2. Description of gas laser apparatus of comparative example

2.1 Structure

2.2 actions

2.3 problems

3. Description of Chamber device of embodiment 1

3.1 Structure

3.2 action/Effect

4. Description of Chamber device of embodiment 2

4.1 Structure

4.2 action/Effect

5. Description of Chamber device of embodiment 3

5.1 Structure

5.2 action/Effect

Embodiments of the present disclosure will be described in detail below with reference to the drawings.

The embodiments described below are merely examples of the present disclosure, and do not limit the present disclosure. Note that the structures and operations described in the embodiments are not necessarily all necessary for the structures and operations of the present disclosure. The same components are denoted by the same reference numerals, and redundant description thereof is omitted.

Fig. 1 is a schematic diagram showing a schematic configuration example of the entire manufacturing apparatus used in an exposure process of the manufacturing apparatus for electronic devices. As shown in fig. 1, the manufacturing apparatus used in the exposure step includes a gas laser apparatus 100 and an exposure apparatus 200. The exposure apparatus 200 includes an illumination optical system 210 and a projection optical system 220, and the illumination optical system 210 includes a plurality of

mirrors

211, 212, and 213. The illumination optical system 210 illuminates the reticle pattern of the reticle stage RT with laser light incident from the gas laser apparatus 100. The projection optical system 220 performs reduction projection of the laser beam having passed through the mask plate, and forms an image on a workpiece, not shown, disposed on the workpiece table WT. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with a photoresist. The exposure apparatus 200 synchronously moves the reticle stage RT and the workpiece stage WT in parallel, thereby exposing the laser light reflecting the reticle pattern on the workpiece. By transferring the device pattern on the semiconductor wafer through the exposure process as described above, a semiconductor device as an electronic device can be manufactured.

2. Description of gas laser apparatus of comparative example

2.1 Structure

A gas laser apparatus of a comparative example will be described. Fig. 2 is a schematic diagram showing a schematic configuration example of the entire gas laser device of this example. As shown in fig. 2, the gas laser apparatus 100 of the present embodiment includes a housing 10, a laser oscillator LO, an energy monitor module 20, and a controller CO as main components. The gas laser apparatus 100 of the present example is an ArF excimer laser apparatus using a mixed gas containing argon (Ar), fluorine (F), and neon (Ne), for example. In this case, the gas laser apparatus 100 emits a pulse laser beam having a center wavelength of approximately 193 nm. The gas laser apparatus 100 may be a gas laser apparatus other than the ArF excimer laser apparatus, and may be a KrF excimer laser apparatus using a mixed gas containing krypton (Kr), fluorine (F), and neon (Ne), for example. In this case, the gas laser apparatus 100 emits a pulse laser beam having a center wavelength of approximately 248 nm. Containing Ar and F as laser medium₂Mixed gas of Kr and F and Ne₂The mixed gas of Ne and Ne is sometimes referred to as a laser gas.

The Control unit CO may be an Integrated Circuit such as a microcontroller, an IC (Integrated Circuit), an LSI (Large-scale Integrated Circuit), an ASIC (Application Specific Integrated Circuit) or an NC (digital Control) device. When the NC device is used, the control unit CO may use a machine learning device or may not use a machine learning device. As described below, several configurations of the gas laser apparatus are controlled by the controller CO.

The laser oscillator LO includes a cavity device CH, a charger BC, a narrowband block 60, and an output coupling mirror OC as main structures.

Fig. 3 is a cross-sectional view of the cavity device CH perpendicular to the traveling direction of the laser light. As shown in fig. 2 and 3, the cavity device CH has a case 30, a pair of

windows

31a, 31b, a pair of

electrodes

32a, 32b, an insulating portion 33, a pulse power module 35, an electrode holder 36, a cross flow fan 38, a motor 38M, a dielectric tube 42, an inner electrode 43, an outer electrode 44, and a plate spring 45 as main structures.

The window 31a and the window 31b are provided at positions opposed to each other in the housing 30. The window 31a is provided at one end in the traveling direction of the laser light in the housing 30, and the window 31b is provided at the other end in the traveling direction of the laser light in the housing 30. As described later, in the gas laser apparatus 100, since light oscillates on the optical path including the housing 30 and laser light is emitted, the laser light generated in the housing 30 is emitted to the outside of the housing 30 through the window 31a and the window 31 b. The

windows

31a and 31b are made of, for example, calcium fluoride. The

windows

31a and 31b may be coated with a film of fluoride, oxide, or the like.

The laser gas is sealed in the case 30. The pair of

electrodes

32a and 32b are arranged along the longitudinal direction of the laser beam, and the pair of

electrodes

32a and 32b are arranged to face each other in the housing 30. The space between the

electrodes

32a and 32b in the case 30 is interposed between the window 31a and the window 31 b. Each of the

electrodes

32a and 32b is a main discharge electrode for exciting the laser medium by glow discharge. In this example, the electrode 32a is a cathode and the electrode 32b is an anode.

An opening is formed in the case 30, and the opening is closed by an insulating portion 33 formed including an insulator. The electrode 32a is supported by the insulating portion 33. A feedthrough hole 34 made of a conductive member is embedded in the insulating portion 33. The feedthrough 34 applies the voltage supplied from the pulse power module 35 to the electrode 32 a. The electrode 32b is supported by the electrode holder 36 and is electrically connected to the electrode holder 36. The electrode holder 36 is electrically connected to the case 30 via a wiring 37.

A charger BC disposed outside the casing 30 is connected to the pulse power module 35. The charger BC is a dc power supply device that charges a capacitor, not shown, provided in the pulse power module 35 with a predetermined voltage. The pulse power module 35 includes a switch controlled by the control unit CO. When the switch is turned on from off, the pulse power module 35 boosts the voltage applied from the charger BC to generate a pulse-like high voltage, and applies the high voltage to the electrode 32a and the inner electrode 43.

The electrode holder 36 is provided with a 1 st lead 41A, a 2 nd lead 41B, and a 3 rd lead 41C. The electrode 32B is sandwiched between the 1 st lead 41A and the 2 nd lead 41B and fixed to the electrode holder 36.

Fig. 4 is a perspective view showing the dielectric tube 42, the inner electrode 43, the outer electrode 44, and the plate spring 45, and fig. 5 is a cross-sectional view of the dielectric tube 42, the inner electrode 43, the outer electrode 44, and the plate spring 45 perpendicular to the traveling direction of the laser light. Fig. 4 shows a state in which the plate spring 45 is separated from the external electrode 44 from the viewpoint of easy observation. As shown in fig. 4 and 5, the dielectric tube 42 has a cylindrical shape, and the longitudinal direction thereof is arranged along the traveling direction of the laser beam. The dielectric tube 42 is made of a dielectric material such as alumina. An internal electrode 43 having a longitudinal direction along the longitudinal direction of the dielectric tube 42 is disposed in the through hole 42H of the dielectric tube 42. As shown in fig. 2, fixed

tubes

42a and 42b are connected to both ends of the dielectric tube 42. A wiring, not shown, connected to one end of the internal electrode 43 is disposed in the through hole of one of the fixed tubes 42a, and a wiring, not shown, connected to the other end of the internal electrode 43 is disposed in the through hole of the other fixed tube 42 b. These wires are connected to the feedthrough holes 34. Accordingly, the feedthrough 34 applies the voltage supplied from the pulse power module 35 to the internal electrode 43 as described above.

The external electrode 44 is in contact with the outer peripheral surface of the dielectric tube 42. The outer electrode 44 is electrically connected to the electrode holder 36. Therefore, the external electrode 44 is electrically connected to the electrode 32b and, further, to the case 30 via the wiring 37. The external electrode 44 includes a contact plate 44C, a step 44L, and a fixing plate 44F. The contact plate 44C has a substantially rectangular plate-like shape, extends in the longitudinal direction of the dielectric tube 42, and contacts the outer peripheral surface of the dielectric tube 42. Specifically, the contact plate 44C is in contact with the outer peripheral surface of the dielectric tube 42 from one end to the other end of the edge portion 44E along the longitudinal direction of the dielectric tube 42.

The step portion 44L includes a plurality of bar members 44B. The bar members 44B are arranged in parallel on the side of the contact plate 44C opposite to the edge 44E in contact with the dielectric tube 42. Therefore, the plurality of bar members 44B are arranged in parallel along the longitudinal direction of the contact plate 44C. In this example, the respective bar sections 44B are parallel to each other. Each strap component 44B includes a 1 st portion 44B1, a flex portion 44BC, and a 2 nd portion 44B 2. The 1 st portion 44B1 is connected to the contact plate 44C and linearly extends in an in-plane direction perpendicular to the longitudinal direction of the dielectric tube 42 in a direction away from the dielectric tube 42. The bent portion 44BC is connected to the 1 st portion 44B1 and bent in the in-plane direction perpendicular to the longitudinal direction of the dielectric tube 42. The 2 nd portion 44B2 is connected to the bent portion 44BC, and extends in an in-plane direction perpendicular to the longitudinal direction of the dielectric tube 42.

The 2 nd portion 44B2 of each strap member 44B is connected to the fixed plate 44F on the side opposite to the side of the inflection portion 44 BC. The fixing plate 44F has a substantially rectangular plate shape, and the longitudinal direction thereof extends along the longitudinal direction of the dielectric tube 42. Therefore, each strip member 44B is connected to an edge portion of the fixed plate 44F along the longitudinal direction of the dielectric tube 42. The fixing plate 44F has a plurality of screw holes 44H formed at substantially equal intervals.

Since the external electrode 44 has the above-described structure, the stepped portion 44L is formed with a plurality of openings 44A surrounded by the contact plate 44C, the pair of strip members 44B, and the fixing plate 44F. The external electrode 44 can be manufactured by, for example, press molding. Specifically, the openings 44A and the screw holes 44H are formed by press-forming 1 metal plate, and the bar members 44B of the stepped portion 44L are three-dimensionally deformed to form the 1 st portion 44B1, the bent portion 44BC, and the 2 nd portion 44B 2. The outer electrode 44 is made of brass, for example. In this case, even when the laser gas containing fluorine is sealed in the case 30 as described above, the surface is passivated, and corrosion by the laser gas can be suppressed. Further, the thickness of the external electrode 44 is, for example, 0.5 mm.

The plate spring 45 has a laminated structure in which a plurality of metal plates having the same shape are stacked. Each metal plate has a substantially rectangular shape. In the present embodiment, the thickness of each metal plate is smaller than the thickness of the external electrode 44, and is, for example, 0.1 mm. In this example, the difference between the thickness of the plate spring 45 and the thickness of the external electrode 44 is, for example, 1 sheet metal or less. For example, the thickness of the plate spring 45 and the thickness of the outer electrode 44 are substantially equal to each other. As described above, if the thickness of the external electrode 44 is 0.5mm, the plate spring 45 is formed by stacking 5 metal plates of 0.1mm, for example. The plate spring 45 has a plurality of screw holes 45H formed therein. The screw holes 45H are provided at positions overlapping the screw holes 44H of the external electrode 44 in a state where the plate spring 45 overlaps the external electrode 44. The outer electrode 44 side of the plate spring 45 is formed in a concave shape, the plate spring 45 is overlapped with the outer electrode 44, screws are screwed into the screw holes 44H and 45H, and after the plate spring 45 and the outer electrode 44 are fixed to each other, the main surface of the plate spring 45 on the outer electrode 44 side presses the outer electrode 44. In this state, one edge 45E of the plate spring 45 along the longitudinal direction of the dielectric tube 42 is positioned on the bent portion 44BC of each strip member 44B. The plate spring 45 is made of brass, for example. In this case, similarly to the external electrode 44, when the laser gas containing fluorine is sealed in the case 30, passivation is formed on the surface, and corrosion can be suppressed.

The outer electrode 44 and the plate spring 45 are fixed to the 2 nd guide 41B by screws S screwed into the

respective screw holes

44H, 45H. Therefore, the 2 nd guide 41B is a fixed member to which the external electrode 44 and the plate spring 45 are fixed. In this state, the leaf spring 45 presses the outer electrode 44 by the entire main surface of the leaf spring 45 in contact with the strip member 44B, and the edge portion 44E of the contact plate 44C of the outer electrode 44 is pressed against and in contact with the outer peripheral surface of the dielectric tube 42. A portion of the outer peripheral surface of the dielectric tube 42 that substantially faces a portion of the contact plate 44C is in contact with the 3 rd guide 41C. Therefore, even if the external electrode 44 presses the dielectric tube 42 by the elastic force of the plate spring 45, the dielectric tube 42 is supported by the 3 rd guide 41C.

The inner electrode 43 and the outer electrode 44 are opposed to each other with the dielectric tube 42 interposed therebetween. By applying a high voltage to the inner electrode 43 and the outer electrode 44, corona discharge is generated in the vicinity of the dielectric tube 42 and the outer electrode 44. The corona discharge assists in the glow discharge generated between the

electrodes

32a, 32 b. Therefore, the inner electrode 43 and the outer electrode 44 are preliminary ionization electrodes for assisting glow discharge by the

electrodes

32a, 32 b.

As shown in fig. 2 and 3, a cross flow fan 38 is disposed in a space on the opposite side of the electrode holder 36 from the electrode 32b side in the casing 10. The space in the casing 30 in which the cross flow fan 38 is disposed and the space between the pair of

electrodes

32a and 32b communicate with each other. Therefore, the cross flow fan 38 rotates, and the laser gas sealed in the housing 30 circulates in a predetermined direction. A motor 38M disposed outside the casing 30 is connected to the cross flow fan 38. The cross flow fan 38 is rotated by the rotation of the motor 38M. The motor 38M is turned on, off, and the rotational speed is adjusted by the control of the control unit CO. Therefore, the controller CO can adjust the circulation speed of the laser gas circulating in the housing 30 by controlling the motor 38M.

A heat exchanger 39 is disposed beside the cross-flow fan 38. At least a part of the laser gas circulated by the cross flow fan 38 passes through the heat exchanger 39, and is temperature-regulated by the heat exchanger 39.

An optical path tube 51 is connected to the one end side of the housing 30 where the window 31a is provided. The output coupling mirror OC is provided on the one end side with respect to the housing 30, and is disposed in the optical path tube 51. The output coupling mirror OC is an optical element on which the laser light emitted from the window 31a enters, and transmits a part of the light emitted from the window 31a, and reflects the other part of the light to return to the inside of the housing 30 through the window 31 a. The output coupling mirror OC is formed of an element in which a dielectric multilayer film is formed on a substrate of calcium fluoride, for example.

An optical path tube 52 is connected to the other end side of the housing 30 on which the window 31b is provided. The narrowing module 60 is connected to the optical conduit 52. Therefore, the narrowing module 60 is provided on the other end side with respect to the housing 30. The narrowband module 60 comprises a housing 61, a grating 62 and

prisms

63, 64. An opening is formed in the housing 61, and the space in the housing 61 and the space in the optical path tube 52 communicate with each other through the opening.

The grating 62 and the

prisms

63 and 64 are disposed in the housing 61. The grating 62 and the

prisms

63 and 64 are optical elements on which the laser light emitted from the window 31b enters. The grating 62 is configured by littrow so that the wavelength dispersion plane substantially coincides with a plane perpendicular to the propagation direction of the laser light, and the incident angle and the diffraction angle of the laser light substantially coincide. In this example, the grating 62 may be an Eschel grating that is blazed for wavelengths of about 193 nm.

At least one of the

prisms

63 and 64 is fixed to the rotary table, and the incident angle of the light incident on the grating 62 is adjusted by slightly rotating the prism of the

prisms

63 and 64 fixed to the rotary table. By adjusting the angle of incidence of the light with respect to the grating 62, the wavelength of the light reflected at the grating 62 is adjusted. Therefore, the light emitted from the window 31b of the housing 30 is reflected by the grating 62 via the

prisms

63 and 64, and the wavelength of the light returning to the housing 30 is adjusted to a desired wavelength. In addition, the number of prisms arranged in the narrowing module 60 is 2 in this example, but may be 1, or may be 3 or more.

The optical resonator is constituted by an output coupling mirror OC and a grating 62 provided with the case 30 interposed therebetween, and the case 30 is disposed on the optical path of the optical resonator. Therefore, the light emitted from the housing 30 reciprocates between the grating 62 of the narrowing-band module 60 and the output coupling mirror OC, and is amplified each time it passes through the laser gain space between the

electrodes

32a and 32 b. A part of the amplified light passes through the output coupling mirror OC and is emitted as pulse laser light.

The energy monitor module 20 is disposed on the optical path of the pulse laser beam emitted from the output coupling mirror OC of the laser oscillator LO. The energy monitor module 20 includes a housing 21, a beam splitter 22, and a pulse energy sensor 23. The housing 21 is connected to the optical conduit 51. The beam splitter 22 and the pulse energy sensor 23 are optical elements on which the laser light emitted from the window 31a is incident. An opening is formed in the housing 21, and the space inside the housing 21 and the space inside the optical path pipe 51 communicate with each other through the opening. A beam splitter 22 and a pulse energy sensor 23 are disposed in the housing 21.

The beam splitter 22 transmits the pulse laser light emitted from the laser oscillator LO with high transmittance, and reflects a part of the pulse laser light toward the light receiving surface of the pulse energy sensor 23. The pulse energy sensor 23 detects the pulse energy of the pulse laser beam incident on the light receiving surface, and outputs data of the detected pulse energy to the control unit CO.

An opening is formed in the case 21 of the energy monitor module 20 on the side opposite to the side to which the optical path tube 51 is connected, and an optical path tube 53 is connected so as to surround the opening. Therefore, the space in the optical path tube 51, the space in the housing 21, and the space in the optical path tube 53 communicate with each other. The light path pipe 53 is connected to the housing 10. A laser emission window OW is provided in the housing 10 at a position surrounded by the optical path tube 53. Therefore, the light transmitted through the beam splitter 22 of the energy monitor module 20 is emitted from the laser emission window OW to the outside of the housing 10 via the optical path tube 53.

The

optical conduits

51, 52, and 53 and the

housings

21 and 61 are filled with purge gas. The purge gas contains an inert gas such as high-purity nitrogen with a small amount of impurities such as oxygen. The purge gas is supplied from a purge gas supply source disposed outside the casing 10 into the

optical conduits

51, 52, 53 and the

casings

21, 61 through unillustrated pipes.

A laser gas supply source LT in which laser gas is accumulated is also disposed outside the housing 10. The laser gas supply source LT supplies a plurality of gases that become laser gas. In this example, the feed comprises F₂And Ar. In addition, if the laser gas is KrF, the laser gas supply source LT supplies a gas containing F₂And Kr. A pipe is connected to the laser gas supply source LT, and the pipe enters the housing 10. The pipe is connected to the laser gas supply device LG. The laser gas supply device LG is provided with a valve and a flow rate control valve, not shown, and is connected to another pipe connected to the housing 30. The laser gas supply device LG is controlled by the control part COThe laser gas is output to the other piping. Therefore, the laser gas supply source LT supplies the laser gas into the housing 30 through the other pipe. The connection portion of the other pipe to the housing 30 is a laser gas supply port LSP for supplying laser gas into the housing 30.

An exhaust device ED is disposed in the casing 10. A pipe connected to the casing 30 is connected to the exhaust device ED. The exhaust device ED exhausts the gas in the casing 30 into the casing 10 through the pipe. At this time, the exhaust device ED adjusts the amount of exhaust gas and the like by a control signal from the control unit CO, and performs a predetermined process on the gas discharged from the casing 30. The connection portion of the pipe to the housing 30 is a laser gas exhaust port LEP that exhausts gas from the inside of the housing 30.

An exhaust pipe 11 is provided in the casing 10. The gas in the casing 10 is discharged from the exhaust pipe 11 to the outside of the casing 10. Therefore, the gas discharged from the exhaust device ED into the casing 10, and the gas discharged from the

optical path pipes

51, 52, 53 and the like into the casing 10 by an unillustrated structure are discharged from the exhaust pipe 11 to the outside of the casing 10.

2.2 actions

Next, the operation of the gas laser apparatus 100 of the comparative example will be described.

Before the gas laser apparatus 100 emits laser light, the inside of the

optical pipes

51, 52, 53 and the inside of the

housings

21, 61 are filled with purge gas by a configuration not shown. In the housing 30, laser gas from the laser gas supply source LT is supplied from the laser gas supply port LSP, and the supplied laser gas is circulated. Specifically, laser gas is supplied into the housing 30 from the laser gas supply port LSP, and gas discharged from the laser gas exhaust port LEP is discharged into the housing 10 via the exhaust device ED, so that the laser gas is enclosed in the housing 30. The controller CO controls the motor 38M to rotate the cross flow fan 38, and the laser gas is circulated by the rotation of the cross flow fan 38.

When the gas laser apparatus 100 emits laser light, the controller CO controls the charger BC and the switches in the pulse power module 35, and applies high voltages between the

electrodes

32a and 32b and between the inner electrode 43 and the outer electrode 44. However, the timing at which the high voltage is applied between the inner electrode 43 and the outer electrode 44 is slightly earlier than the timing at which the high voltage is applied between the

electrodes

32a and 32 b. When a high voltage is applied between the inner electrode 43 and the outer electrode 44, corona discharge is generated in the vicinity of the dielectric tube 42, and ultraviolet light is emitted. When a high voltage is applied between the

electrodes

32a and 32b, the insulation between the

electrodes

32a and 32b is broken, and discharge occurs. The energy of the discharge causes the laser medium contained in the laser gas between the

electrodes

32a and 32b to be excited, and when returning to the ground state, the laser medium emits natural emission light. A part of the light exits the window 31b and is reflected by the grating 62 via the

prisms

63 and 64. The light reflected by the grating 62 and propagated again into the housing 30 through the window 31b is narrowed. The narrowed light induces and emits the laser medium in an excited state, and the light is amplified. Thus, light of a predetermined wavelength resonates between the grating 62 and the output coupling mirror OC, and laser oscillation occurs. Then, a part of the laser light passes through the output coupling mirror OC and is emitted from the laser emission window OW.

At this time, the laser beam reflected by the beam splitter 22 is received by the pulse energy sensor 23, and the pulse energy sensor 23 outputs a signal based on the intensity of the received energy of the laser beam to the control unit CO. The control unit CO controls the charger BC and the pulse power module 35 based on the signal, and adjusts the power of the emitted laser beam.

2.3 problems

As described above, the external electrode 44 is pressed against the dielectric tube 42 by the plate spring 45, and one end to the other end of the edge portion 44E of the contact plate 44C is in contact with the dielectric tube 42. However, the outer peripheral surface of the dielectric tube 42 may be deformed as shown in fig. 6. When a high voltage is applied between the inner electrode 43 and the outer electrode 44a plurality of times, the contact plate 44C of the outer electrode 44 may be unevenly worn as shown in fig. 7. In these cases, a gap a may be formed between the outer peripheral surface of the dielectric tube 42 and the contact plate 44C. When the gap a is formed between the outer peripheral surface of the dielectric tube 42 and the contact plate 44C, it is difficult to perform uniform corona discharge along the longitudinal direction of the dielectric tube 42. Therefore, it is difficult to perform uniform glow discharge between the

electrodes

32a and 32 b. Therefore, amplification of the laser light in the space between the

electrodes

32a and 32b is unstable, and it may be difficult to stably emit the laser light.

Therefore, in the following embodiments, a cavity device capable of realizing a gas laser device capable of stably emitting laser light is exemplified.

3. Description of Chamber device of embodiment 1

Next, the chamber device of embodiment 1 will be explained. The same components as those described above are denoted by the same reference numerals, and redundant description is omitted unless otherwise specified.

3.1 Structure

Fig. 8 is a perspective view showing the dielectric tube 42, the inner electrode 43, the outer electrode 44, and the plate spring 45 of the cavity device CH in the present embodiment by the same method as fig. 4. Fig. 9 is a sectional view showing the dielectric tube 42, the inner electrode 43, the outer electrode 44, and the plate spring 45 of the cavity device CH in the present embodiment by the same method as fig. 5. As shown in fig. 8, the plate spring 45 of the present embodiment includes a plurality of plate-spring pieces 45P divided by slits 45S, and the slits 45S are cut out from an edge 45E along the longitudinal direction of the dielectric tube 42. Therefore, the plate spring piece 45 includes a pair of main surfaces that are opposed to each other and interposed between the slits 45S. In the present embodiment, the longitudinal direction of each slit 45S is perpendicular to the edge 45E. The width of the slit 45S is, for example, 1mm or more and 10mm or less. The leaf spring 45 has a fixing portion 45F extending in the longitudinal direction of the dielectric tube 42 at a portion where the slit 45S is not formed, and each leaf spring 45P is connected to the fixing portion 45F on the side opposite to the edge portion 45E side. A screw hole 45H is formed in the fixing portion 45F.

Each plate spring 45P includes a bent portion 45B bent along the edge portion 45E. As shown in fig. 9, the plate spring piece 45P is convex on the side opposite to the external electrode 44 side by the bent portion 45B, and the plate spring piece 45P is separated from the external electrode 44 in the bent portion 45B. In the present embodiment, the edge 45E is in contact with each strip member 44B of the outer electrode 44, and presses the strip member 44B. Therefore, the leaf spring 45 presses the strip member 44B on the edge 45E side of the bent portion 45B. In the present embodiment, the edge portion 45E of the leaf spring piece 45P presses the inflection portion 44BC in the strip member 44B. In fig. 9, the boundaries of the 1 st portion 44B1, the inflection portion 44BC, and the 2 nd portion 44B2 are shown by dashed lines. The inflection portion 44BC is a portion extending from a position where the strip piece 44B starts to curve from the 1 st portion 44B1 side to a position 5 times the thickness T of the strip piece 44B from the 1 st portion 44B1 when viewed in the longitudinal direction of the 1 st portion 44B 1. In fig. 9, a position 5T apart from 1 st portion 44B1 by 5 times the thickness T of strip member 44B when viewed in the longitudinal direction of 1 st portion 44B1 is shown. For example, when the thickness of the outer electrode is 0.5mm as described above, the bent portion 44BC is located from the position where the strip member 44B starts to bend from the 1 st portion 44B1 side to the position 2.5mm away from the 1 st portion 44B1 when viewed in the longitudinal direction of the 1 st portion 44B 1. The edge 45E of the plate spring 45P presses an arbitrary region of the bent portion 44 BC.

Fig. 10 is a view of the dielectric tube 42, the external electrode 44, and the plate spring 45 of the cavity device CH in the present embodiment as viewed from a direction perpendicular to the longitudinal direction of the dielectric tube 42. As shown in fig. 10, the slit 45S of the plate spring 45 of the present embodiment is provided between the respective strip members 44B. Thus, each plate spring 45P presses the strip member 44B individually.

3.2 action/Effect

Fig. 11 is a diagram showing a state in which the outer peripheral surface of the dielectric tube 42 is deformed as shown in fig. 6, and fig. 12 is a diagram showing a state in which a part of the external electrode 44 is unevenly worn as shown in fig. 7. In the chamber device CH of the present embodiment, the plate spring 45 includes a plurality of plate-spring pieces 45P divided by slits 45S, and the slits 45S are cut out from an edge 45E along the longitudinal direction of the dielectric tube 42. Each plate spring 45P can press the outer electrode 44 individually. Therefore, as shown in fig. 11, even when the outer peripheral surface of the dielectric tube 42 is deformed, the following ability of the external electrode 44 to the surface of the dielectric tube 42 can be improved as compared with the case of using the plate spring 45 of the comparative example. In fig. 11, a state in which the plate spring 45P does not follow the deformed portion of the dielectric tube 42 is shown by a broken line. Further, as shown in fig. 12, in the case where a part of the external electrode 44 is unevenly worn, the surface conformability of the external electrode 44 to the dielectric tube 42 can be improved as compared with the case where the plate spring 45 of the comparative example is used. In fig. 12, a state in which the plate spring 45P does not follow the unevenly worn portion of the outer electrode 44 is shown by a broken line. Therefore, occurrence of a gap between the dielectric tube 42 and the external electrode 44 can be suppressed. In the chamber device CH of the present embodiment, the plate spring piece 45P includes the bent portion 45B bent along the edge portion 45E, and the strip member 44B is pressed on the edge portion 45E side of the bent portion 45B. With this configuration, the plate spring 45P can be suppressed from flexing, and the plate spring 45P can stably press the strip member 44B. Therefore, the plate spring 45 can stably press the external electrode 44 against the dielectric tube 42, and as described above, occurrence of a gap between the dielectric tube 42 and the external electrode 44 can be suppressed. Therefore, according to the cavity device CH of the present embodiment, a gas laser device capable of stably emitting laser light can be realized. Therefore, the gas laser apparatus 100 of the present embodiment can stably emit laser light.

In the chamber device CH of the present embodiment, the slits 45S formed in the leaf spring 45 are provided between the strip members 44B, and the strip members 44B are individually pressed by the leaf springs 45P. That is, the bar members 44B and the leaf spring pieces 45P correspond one-to-one. Therefore, the surface conformability of the external electrode 44 to the dielectric tube 42 can be improved as compared with the case where one plate spring 45P presses the plurality of strip members 44B. Therefore, occurrence of a gap between the dielectric tube 42 and the external electrode 44 can be further suppressed. Further, unlike the present embodiment, one plate spring 45P may press a plurality of bar members 44B.

In the cavity device CH of the present embodiment, the longitudinal direction of the slit 45S is perpendicular to the edge 45E. Therefore, the pressing force of the plate spring 45P on the bar member 44B can be suppressed from changing depending on the position along the edge 45E in the plate spring 45P. Unlike the present embodiment, the longitudinal direction of the slit 45S may not be perpendicular to the edge 45E.

In the chamber device CH of the present embodiment, the plate spring 45 presses the strip member 44B by the edge 45E of the plate spring piece 45P. Therefore, the plate reed 45P can be suppressed from being unnecessarily enlarged.

In the cavity device CH of the present embodiment, the leaf spring 45 presses the bent portion 44BC of the strip member 44B. Therefore, the elastic force of the plate spring 45 can be efficiently transmitted to the contact plate 44C of the outer electrode 44. Therefore, the surface followability of the external electrode 44 to the dielectric tube 42 can be further improved as compared with the case where the plate spring 45 presses the 2 nd portion 44B2 of the strip member 44B. Therefore, occurrence of a gap between the dielectric tube 42 and the external electrode 44 can be further suppressed. In addition, unlike the present embodiment, the plate spring 45 may press the 2 nd part 44B2 of the bead member 44B.

In the chamber device CH of the present embodiment, the plate spring 45 has a laminated structure in which a plurality of metal plates are stacked. Therefore, the range of elastic deformation of the plate spring 45 is wider than that in the case where the plate spring 45 is formed of one metal plate, and the plate spring 45 can exert an elastic force and be suppressed from being plastically deformed. Unlike the present embodiment, the plate spring 45 may be formed of a single metal plate.

4. Description of Chamber device of embodiment 2

Next, the chamber device of embodiment 2 will be explained. The same components as those described above are denoted by the same reference numerals, and redundant description is omitted unless otherwise specified.

4.1 Structure

Fig. 13 is a sectional view showing the dielectric tube 42, the inner electrode 43, the outer electrode 44, and the plate spring 45 of the cavity device CH in the present embodiment by the same method as fig. 5. As shown in fig. 13, the plate spring piece 45P of the plate spring 45 of the present embodiment extends to a position overlapping with the 1 st part 44B 1. Therefore, in the plate spring 45 of the present embodiment, the bent portion 44BC of the bead member 44B is pressed by the main surface of the plate spring piece 45P.

4.2 action/Effect

According to the cavity device CH of the present embodiment, the leaf spring 45 presses the bent portion 44BC of the bar member 44B by the main surface of the leaf spring piece 45P, and therefore, the contact area between the bar member 44B and the leaf spring 45 can be enlarged. Therefore, the outer electrode 44 can be prevented from being damaged by the force received from the plate spring 45.

5. Description of Chamber device of embodiment 3

Next, the chamber device of embodiment 3 will be explained. The same components as those described above are denoted by the same reference numerals, and redundant description is omitted unless otherwise specified.

5.1 Structure

Fig. 14 is a perspective view showing the dielectric tube 42, the inner electrode 43, the outer electrode 44, the plate spring 45, and the 2 nd guide 41B of the cavity device CH in the present embodiment. The plate spring 45 of the present embodiment is different from the plate spring 45 of embodiment 1 in that the slit 45S extends to the 2 nd guide 41B. As described above, the 2 nd guide 41B is a fixing member fixing the external electrode 44 and the plate spring 45. Therefore, in the plate spring 45 of the present embodiment, the slit 45S extends to the fixing part that fixes the external electrode 44 and the plate spring 45.

5.2 action/Effect

According to the cavity device CH of the present embodiment, the slit 45S of the plate spring 45 extends to the 2 nd guide 41B as the fixed member, and therefore, the movable range of each plate spring piece 45P is larger than the case where the slit 45S does not extend to the 2 nd guide 41B. Therefore, even when the deformation of the outer peripheral surface of the dielectric tube 42 is large and the degree of uneven wear of the external electrode 44 is large, the external electrode 44 can be pressed against the outer peripheral surface of the dielectric tube 42. Therefore, also in these cases, occurrence of a gap between the dielectric tube 42 and the external electrode 44 can be suppressed.

The above description is not limiting, but is simply illustrative. Accordingly, it will be apparent to those skilled in the art that modifications can be made to the embodiments of the disclosure without departing from the claims. Furthermore, it is also apparent to those skilled in the art that the embodiments of the present disclosure are used in combination.

Unless explicitly stated otherwise, the terms used throughout the specification and claims should be interpreted as "non-limiting" terms. For example, a term "comprising" or "includes" should be interpreted as "not being limited to the portion described as being included". The term "having" should be interpreted as "not limited to the portion described as having". In addition, the indefinite article "a" should be construed to mean "at least one" or "one or more". Further, a phrase "at least one of A, B and C" should be interpreted as "A", "B", "C", "A + B", "A + C", "B + C", or "A + B + C". Further, combinations of these and portions other than "a", "B", and "C" should be interpreted as being included.

Claims

1. A cavity device for laser, comprising:

a tube of dielectric;

an inner electrode extending in a longitudinal direction of the tube and disposed in the through hole of the tube;

an external electrode including a contact plate extending in a longitudinal direction of the tube and contacting an outer circumferential surface of the tube, and a step portion formed of a plurality of strip members having one ends connected to the contact plate, the plurality of strip members being arranged in parallel in the longitudinal direction of the contact plate; and

a plate spring extending in a longitudinal direction of the tube and pressing the outer electrode against the tube,

the plate spring includes a plurality of plate-spring pieces divided by slits cut out from an edge portion along a longitudinal direction of the tube,

the plate spring piece includes a bent portion bent along the edge portion, and presses the strip member on the edge portion side of the bent portion.

2. The cavity device for laser according to claim 1,

the laser cavity device further includes a fixing member extending in a longitudinal direction of the tube and fixing the outer electrode and the plate spring by pressing the outer electrode and the plate spring,

the outer electrode includes a fixing plate extending along a length direction of the tube, connected to the other end of each of the strip parts, and fixed to the fixing part,

the plate spring includes a fixing portion extending in a longitudinal direction of the tube, connected to a side of each of the plate spring pieces opposite to the edge portion side, and fixed to the fixing member,

the slit extends to the fixing member.

3. The cavity device for laser according to claim 1,

the slits are provided between the respective strip members, and the respective leaf springs individually press the strip members.

4. The cavity device for laser according to claim 1,

the longitudinal direction of the slit is perpendicular with respect to the edge portion.

5. The cavity device for laser according to claim 1,

the plate spring presses the strip member with the rim portion of the plate spring.

6. The cavity device for laser according to claim 1,

each of the bar members includes a 1 st portion connected to the contact plate and extending in a direction away from the pipe, a bent portion connected to the 1 st portion and bent, and a 2 nd portion connected to the bent portion in a plane direction perpendicular to a longitudinal direction of the pipe,

the plate spring presses the bent portion.

7. The cavity device for laser according to claim 6,

the leaf spring presses the bent portion of the strip member with a main surface of the leaf spring.

8. The cavity device for laser according to claim 1,

the plate spring has a laminated structure in which a plurality of metal plates are stacked.

9. The cavity device for laser according to claim 8,

the difference between the thickness of the plate spring and the thickness of the outer electrode is less than the thickness of 1 sheet of the metal plate.

10. The cavity device for laser according to claim 1,

the outer electrode is made of copper and is,

the leaf spring is composed of brass.

11. The cavity device for laser according to claim 1,

the width of the slit is 1mm to 10 mm.

12. A gas laser device having a cavity device for laser, wherein,

the cavity device for laser comprises:

a tube of dielectric;

an inner electrode disposed in the through hole of the tube;

13. The gas laser apparatus according to claim 12,

the gas laser device further comprises a fixing member extending in the longitudinal direction of the tube and fixing the outer electrode and the plate spring by pressing them,

the slit extends to the fixing member.

14. The gas laser apparatus according to claim 12,

15. The gas laser apparatus according to claim 12,

16. The gas laser apparatus according to claim 12,

17. The gas laser apparatus according to claim 12,

the plate spring presses the bent portion.

18. The gas laser apparatus of claim 17,

19. The gas laser apparatus according to claim 12,

20. A method for manufacturing an electronic device, comprising the steps of:

laser light is generated in a gas laser apparatus having a laser cavity apparatus,

the laser light is output to an exposure device,

exposing the laser light on a photosensitive substrate in the exposure apparatus to manufacture an electronic device,

the cavity device for laser comprises:

a tube of dielectric;

an inner electrode disposed in the through hole of the tube;